Arthur2 wrote:
"The Medway Handyman" wrote in message
m...
B&Q takes wind turbines off shelves Turbine range withdrawn from sale
after recent survey reveals they don't work as effectively as first
thought

http://www.diyweek.net/news/news.asp?id=11999





This subject has been on my mind for the past 2 days.
All wind turbines seem to be blades mounted vertically on a horizontal
axle/axis.
These can only be 100% efficient if the wind blows directly onto the face of
the blades.

That is why these things have a big tail fin and a turbine body that is
free to rotate - they should always face the wind if there is a nice
steady flow. Needless to say in an urban environment with turbulent flow
they can't ever really face the wind since it gusts from all over the
place.

If instead of blades they had the things you see on some wid speed
measurement devices

Anemometer?


that have 3 or more cup shaped receptacles on horizontal bars fixed to a
vertical axis.
The wind can hit these assemblies at any angle it chooses with no difference
to the efficiency
of the 'machine'.

That is what the tail does really...

http://en.wikipedia.org/wiki/Anemometer



--
Cheers,

John.

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